ARGO - Development of next-generation argon dark matter search

暗物质问题自20世纪30年代以来一直存在，从那时起，我们一直在星系或星系团中发现大量过量的物质，超出了我们对常规物质的观察所能解释的范围，这强烈暗示着存在一种尚未发现的物质形式，它遍布宇宙，远远超过常规物质，大约是5比1的倍数。直接观测暗物质粒子对天体物理学和粒子物理学都有重要意义。对于高质量的暗物质粒子，所提出的实验方案具有很强的灵敏度，仍然是寻找暗物质的非常可行的候选者。在成功证明氩气是暗物质的目标之后，DEAP-3600合作项目加入了一个新的全球氩气暗物质合作项目，旨在分阶段在SNOLAB建立一个最终的数百吨暗物质氩气探测器，该探测器对中微子层具有最终的灵敏度，由中微子相互作用背景限制进一步灵敏度的区域定义。该计划的第一步是DarkSide-20k （DS-20k）实验，该实验已经在意大利的LNGS建造中，利用20吨氩的敏感目标，随后是更大的探测器ARGO。我们在此请求支持ARGO概念的早期发展。该研究包括开发详细的探测器模拟和评估，以及光电探测器选项的评估，以确定探测器性能使用波长移频器（如所有以前的氩暗物质探测器所使用的），或使用新型的紫外线敏感光电探测器，以及开发一个完整的探测器背景模型。该研究的一个重要组成部分包括进一步开发新型和大面积3D数字硅光电倍增管，这是长期氩暗物质计划的关键组成部分。这项由研究团队首创的新技术将彻底改变单光子的探测，其广泛的应用不仅可以改善天体粒子物理实验，还可以改善无数其他潜在的科学和商业可能性。利用加拿大强大的工业关系，尽早对这些设备的生产和可靠性进行研究，以确保能够满足所需的性能，这在战略上具有重要意义。拟议的研究还包括与提取数百吨低放射性氩有关的开发——一种放射性同位素39Ar的超灵敏测定系统。该研究计划包括新型探测器的开发，建立在现有投资和专业知识的基础上，与工业合作伙伴和400多名成员的全球氩暗物质合作关系密切。这项研究将为未来的暗物质实验计划奠定基础，并为HQP培训提供了强大的机会。

The dark matter problem has been around since the 1930's, since which time we have consistently found a significant excess of matter in galaxies or galaxy clusters beyond that explained by our observations of conventional matter, implying strongly that there exists a yet undiscovered form of matter that pervades the universe and far outweighs the conventional matter, by a factor of approximately 5 to 1. Direct observation of a dark matter particle would have strong implications for both astrophysics and particle physics. High-mass dark matter particles, for which the proposed experimental program has strong sensitivity, remain as very viable candidates in the search for dark matter. After the successful demonstration of argon as a dark matter target, the DEAP-3600 collaboration has joined in founding a new Global Argon Dark Matter Collaboration aimed at a phased approach towards an ultimate multihundred tonne argon detector for dark matter at SNOLAB, with ultimate sensitivity to the neutrino floor, defined by the region where backgrounds from neutrino interactions limit further sensitivity. The first step in that program is the DarkSide-20k (DS-20k) experiment, already under construction at LNGS in Italy, utilizing a sensitive target of 20 tonnes of argon, to be followed by the larger detector - ARGO. We are requesting here support for the early development of the ARGO concept. The research includes development of a detailed detector simulation and evaluation and evaluation of photodetector options to determine detector performance using wavelength-shifters (as all previous argon dark matter detectors have used), or using novel UV-sensitive photodetectors, as well development of a full detector background model. A strong component of the research includes the further development of novel and large-area 3D digital silicon photomultipliers, which are a crucial enabling component of the long-term argon dark matter program. This new technology, being pioneered by the research team, will revolutionize the detection of single photons, with broad applications that will allow improvements in not only astroparticle physics experiments, but also with a myriad of other potential scientific and commercial possibilities. It is strategically important to undertake early the study of the production and reliability of these devices, taking advantage of strong industrial ties in Canada, to ensure the required performance can be met. The proposed research also includes development related to the extraction of several hundred tonnes of low-radioactivity argon - an ultrasensitive assay system for the radioactive isotope 39Ar. The research program includes novel detector development, builds on existing investments and expertise, has strong ties to industrial partners and the over 400-member Global Argon Dark Matter collaboration. The research will lay the groundwork for the future experimental dark matter program, with strong opportunities for HQP training.